Walls of Sound: The acoustic field of multiple vessels hammering on metal pipes

Transcription

1 Walls of Sound: The acoustic field of multiple vessels hammering on metal pipes 3/17/ draft Val Veirs Beam Reach Marine Science and Sustainability School The following document is a short report on acoustic data taken during the 3/30/2013 Killer Whale Hazing Drill I wish to thank my able assistants: Jason Wood (acoustics), Eric Adelberger (Laser ranging) and Scott Hearning (photography) On the following pages I have summarized the physical and acoustic situation for each of the separate sound files that were recorded on the Gato Verde. The recordings were made with a calibrated InterOcean hydrophone and were recorded at a sampling rate of 48,000 samples per second on a Marantz solid state recorder. Analysis was performed with Audacity and acoustic analysis software that I have written. GPS data were analyzed and spatial plots were made with the program R. Pipe banging vessels in position across Upright Channel while Orcas ferry passes behind. Passing pinniped apparently unperturbed.

2 Question? Can anyone confirm that Waldron Freight was in front of the line of vessels at the beginning of our exercise? Distance to the line: 1000 meters Sound file : 3 Calibration scale: 130 Average sound level (rms) 114 db re 1 micropa Peak sound level (rms) 123 db re 1 micropa over 60 ms window

3 Time series of a single bang above with corresponding spectrum levels in db re 1 micropa^2/hertz vs frequency in khz below. Note the harmonic peaks at 1 khz and its multiples. (Detail below)

4 Distance to the line: 800 meters Average sound level (rms) 108 db re 1 micropa Sound file : 4 Peak sound level (rms) 116 db re 1 micropa over 60 ms window Calibration scale: 120 Note: Some of the pings are clipped

5 Distance to the line: 800 meters Sound file : 5 Calibration scale: 140 Average sound level (rms) 125 db re 1 micropa Peak sound level (rms) 134 db re 1 micropa over 60 ms window Background between pings (rms) 123 db re 1 micropa

6 Distance to the line: 1000 meters Average sound level (rms) 125 db re 1 micropa Sound file : 7 Peak sound level (rms) Calibration scale: 130 Note: File is clipped, speedboat is passing, pings barely audible (see vertical lines in spectrogram)

7 Distance to the line: 800 meters Sound file : 8 Calibration scale: 140 Average sound level (rms) 118 db re 1 micropa Peak sound level (rms) 123 db re 1 micropa over 60 ms window Background (rms) 114

8 Distance to the line: 400 meters Sound file : 9 Calibration scale: 140 Average sound level (rms) 124 db re 1 micropa Peak sound level (rms) 131 db re 1 micropa over 60 ms window Background (rms) 114

9 Distance to the line: 380 meters Sound file : 11 Calibration scale: 140 Average sound level (rms) 121 db re 1 micropa Peak sound level (rms) 130 db re 1 micropa over 60 ms window Background (rms) 117

10 Distance to the line: 370 meters Average sound level (rms) 121 db re 1 micropa Sound file : 12 Peak sound level (rms) 134 db re 1 micropa over 60 ms window Calibration scale: 150 Background (rms) 116 Note: Pipe harmonics are present all the time, loudest pings clipped

11 Distance to the line: 220 meters Sound file : 13 Calibration scale: 150 Note: loudest pings clipped Average sound level (rms) 131 db re 1 micropa Peak sound level (rms) 146 db re 1 micropa over 60 ms window Background (rms) 116

12 Distance to the line: 100 meters Sound file : 14 Calibration scale: 160 Average sound level (rms) 132 db re 1 micropa Peak sound level (rms) 147 db re 1 micropa over 60 ms window Background (rms) 119

13 Distance to the line: 125 meters Sound file : 15 Calibration scale: 150 Average sound level (rms) 131 db re 1 micropa Peak sound level (rms) 140 db re 1 micropa over 60 ms window Background (rms) 123

14 Distance to the line: 130 meters Sound file : 16 Calibration scale: 160 Average sound level (rms) 129 db re 1 micropa Peak sound level (rms) 140 db re 1 micropa over 60 ms window Background (rms) 119

15 Distance to the line: 500 meters Average sound level (rms) 127 db Sound file : 17 Peak sound level (rms) Calibration scale: 140 Background (rms) Note: Hear ferry clearly No pings detected

16 Distance to the line: 400 meters Average sound level (rms) 126 db re 1 micropa Sound file : 18 Peak sound level (rms) 133 db re 1 micropa over 60 ms window Calibration scale: 140 Note: Hear ferry clearly and airplane passes overhead at 3:38:30 (1:33 in file), no pings

17 Distance to the line: 500 meters Average sound level (rms) 123 db Sound file : 19 Peak sound level (rms) Calibration scale: 130 Background (rms) Note: Ferry is very badly clipped in this file and we hear no pings

18 Distance to the line: 400 meters Average sound level (rms) Sound file : 20 Peak sound level (rms) Calibration scale: 130 Background (rms) Note: Vessels have doubled the line, terrible flow noise and no pings

19 Distance to the line: 400 meters Average sound level (rms) 123 db re 1 micropa Sound file : 22 Peak sound level (rms) 133 db re 1 micropa over 60 ms window Calibration scale: 140 Background (rms) 114 Notes:Line has been doubled, loudest pings clipped

20 Distance to the line: 400 meters Sound file : 23 Calibration scale: 150 Note: Line is doubled Average sound level (rms) 124 db re 1 micropa Peak sound level (rms) 132 db re 1 micropa over 60 ms window Background (rms) 116 db

21 Distance to the line: 300 meters Average sound level (rms) 125 db re 1 micropa Sound file : 27 Peak sound level (rms) 141 db re 1 micropa over 60 ms window Calibration scale: 160 Background (rms) 118 (after speed boat at beginning) 123 earlier Note: Single pipe, empty, distance is to Sea Goose

22 A couple of pings: (Waveform above and Spectrogram below)

23 Distance to the line: 300 meters Average sound level (rms) 126 db re 1 micropa Sound file : 28 Peak sound level (rms) 138 db re 1 micropa over 60 ms window Calibration scale: 160 Background (rms) 118 db Note: Single pipe filled, distance is to Sea Goose

24 A couple of pings: (Waveform above and Spectrogram below)